The present invention relates to a method for forming a production plan and an apparatus for forming a production plan.
Recently, with a technological innovation and a change of social structure for consumers, styles of production activities have been rapidly changing in the manufacturing industry to involve a wide variety and small number of goods or productions, short delivery time, and short life cycle. To cope with such a change of styles of production activities, systematization by computer has been more and more introduced into the manufacturing industry. In forming a production plan, it is becoming indispensable to manage automation by computer to form a production plan with high precision and a good efficiency.
In particular, a thin film formation process of semiconductors or liquid crystals or the like devices has many manufacturing processes, uses the same manufacturing apparatus for a plurality of times, or includes a complex manufacturing process repeating a plurality of similar manufacturing processes. In addition, a thin film formation process is a manufacturing process which is influenced greatly in the quality of the production lots due to the holding times of production lots and by the difference of process precisions of respective manufacturing apparatus. In such a complex manufacturing process, a lot of data are handled, and the manufacturing process have a variety of limitation items in manufacturing that should be taken into consideration in forming a production plan. Accordingly it is becoming more and more difficult for workers to form a plan with a good precision in real time manually, and to provide respective manufacturing apparatuses or automatic carrier units with proper production instructions.
Referring to FIG. 7, a production plan forming apparatus using a computer of a prior art is described as follows. FIG. 7 is a block diagram showing the constitution of a production plan forming apparatus according to a prior art.
As shown in FIG. 7, the conventional production plan forming apparatus comprises a central processing unit 101 having a computer, a memory unit 102 for storing a variety of data, an input unit 103 for inputting data necessary for forming a production plan, and a display unit 104 for displaying a formed production plan.
The central processing unit 101 has an event receiving part 105 for receiving a change of production conditions as an event such as a start and a finish of production by a manufacturing apparatus and a start and a finish of production of production lots. And the central processing unit 101 has a dispatching part 106 for indicating a production by forming a production plan.
The memory unit 102 stores basic data necessary for forming a production procedure of the production lots and a production plan including information on manufacturing apparatuses necessary for production, and condition data changing with time such as production lots and condition of the apparatus.
The central processing unit 101 collectively controls the input unit 103, the memory unit 102 and the display unit 104, and manages for forming a production plan according to a predetermined processing program by utilizing the event receiving part 105 and the dispatching part 106.
Next, the operation of the above-mentioned apparatus for forming a prior art production plan will be described in detail with reference to FIG. 7.
This apparatus for forming a production plan receives, as an event, a change of production state when the production state has got the change such as a start and a finish of production of the production lots, and a start and a stop of the operation of the manufacturing apparatus. And the apparatus for forming a production plan automatically forms as required a production plan, as well as carries out a production indication, namely production instruction with respect to the manufacturing apparatuses and production lots with a change in the production state according to the event received.
A manufacturing worker needs to carry out a production procedure different from usual case in order to reproduce the production lots, of which quality has deteriorated due to an excess of the holding time in specific manufacturing processes or is found to be a problem in the inspection process. In this case, a production procedure of this time should be indicated as a manual production.
A sampling test for the production lots is carried out at a constant interval in the lots produced. Depending on the test result, introduction control had to be carried out for the lots already produced or the lots to be produced afterwards. With respect to the process requiring such a complicated limitation, a manufacturing worker removes the lots from target number of products of the production plan and carried out the production indication completely manually.
On thin film formation processes in manufacturing semiconductors or liquid crystals, the quality of the production lots is greatly influenced by the time that production lots were held in the manufacturing process. In a conventional apparatus for forming a production plan, however, production indications are carried out only when the production state changed. Accordingly, in the manufacturing processes with restriction of the strict holding time, a time lag occurs between a time when a production indication is necessary and a time when a production indication is actually held thus causing a problem that the production lots are unnecessarily held. For example, in case a process for manufacturing needs more time than its previous process, a production indication is held so that the previous process is finished its production at the time when the subsequent process finishes its production. Thereby the holding time in the manufacturing processes was reduced.
In addition, it was practically very difficult for a manufacturing worker to carry out a production indication for a production lot exceeding the holding limitation time to be sent to a recovery process immediately, by comparing the holding time for the entire production lots and a holding limitation time that differs depending on each manufacturing process. Accordingly, in such a case, there is a problem that effective production can not be carried out due to a delay of response.
It was necessary to control the introduction of the production lot in the previous process based on the number of the production lot in process during the manufacturing process, in order to keep the holding time of the production lot within the limitation time. And controlling of the introduction of the production lot at the previous process as mentioned above was made, in order to enhance the operation rate of the manufacturing apparatus in the manufacturing process using the same manufacturing apparatus for a plurality of times, and in the manufacturing process for a similar manufacturing process repeated a plurality of times. A conventional apparatus for forming a production plan, however, has a problem that unnecessary in-process lots are stopped at the subsequent process because production indications are sent as required to the manufacturing apparatuses which are not producing in case there is a lot which is operable for production.
A manufacturing process which carries out productions repetitively has also a problem that a manufacturing step free from a lot for producing occurs because the subsequent process differs depending on the lot to be produced.
In a conventional apparatus for forming a production plan, it is necessary to inspect production lots at a certain interval for the lots produced and to control the introduction of the lots already produced or the lots to be produced afterwards depending on the result of the inspection. In such case, in a conventional apparatus for forming a production plan, different lots are inspected depending on the turn of the lot produced, and it was necessary to examine the production lots whether they are proceeded for the next process or for the recovering process after the second inspection, depending on the result of the inspection. Accordingly, there is a problem that it takes a long time for the inspection result to be reflected in the production.
There is also a problem that, optimizing the production indication is difficult, and in some cases, re-inspection happens to be made for the production lots unnecessary in reality.
In a conventional apparatus for forming a production plan, a manufacturing worker can not make such meticulous control that according to actual state such as to stop a particular production lot in its production progress or to stop a particular manufacturing apparatus or a particular automatic production of the manufacturing process. Accordingly, there is also a problem that some production lots could be carried out many times to a manufacturing apparatus against the intention of the manufacturing worker or lots in process could not be held intentionally by the manufacturing worker.
It is the purpose of the present invention to provide a method for forming a production plan and an apparatus for forming the same. In a complex and large-scale manufacturing process with many manufacturing apparatuses and manufacturing processes as well as similar productions repeatedly carried out, the method for forming a production plan and the apparatus for forming the same form a production plan rapidly and most suitably in consideration of limitations in each manufacturing process and carry out a production indication.
To achieve the above purpose, a method for forming a production plan according to the present invention comprises:
an event receiving process for receiving, as an event, a change of production state based on basic data necessary for forming a production procedure of production lots or a production plan having information on manufacturing apparatus necessary for production, and state data changing with time indicating state of said production lots and said manufacturing apparatus;
an event reservation process for forming event data by determining a time when an event reservation part carries out an production indication and an event generated at that time in case a time when an event occurs and a time when a production indication is carried out are different;
a pseudo event generation process for generating a pseudo event at a time when said event data is referred to a certain time interval and should be processed; and
a process for carrying out a production indication by determining a production lot produced with said manufacturing apparatus by said pseudo event at a different time from a time when said event occurred, by using a dispatching part which determines a production lot to be produced with a manufacturing apparatus in connection with said event, and determines a manufacturing apparatus to produce next to a production lot in connection with said event, from said event or said pseudo event.
By means of the above-mentioned method for forming a production plan according to the present invention, an event data are formed with respect to an event of which time when the production state changed is different from the time when the production indication is carried out. And by a pseudo event generation part, a pseudo event is generated based on the event data at the time when the production indication is held. By determining the lots to be produced by the manufacturing apparatus in connection with an event using the dispatching part and by determining the manufacturing apparatus to be produced after the production lot in connection with an event, from said event or said pseudo event, a production plan is formed and a production indication is carried out. Accordingly even at a time when production state doesn""t change by taking limitations in each process into consideration by the pseudo event, a production plan can be formed and a production indication can be carried out rapidly and most suitably.
In the above-mentioned constituents of the method for forming a production plan, it is desirable to further comprise:
a comparison process for comparing a holding time of entire production lots and a limitation time respectively from limitation time data with respect to a minimum time said production lots have to hold and a maximum time said production lots are able to hold in manufacturing processes in connection with production orders, and production history data having recorded a time of production of each manufacturing process of each of said production lots;
a limitation time judgment process for forming and outputting limitation time state data by judging an observance state of the limitation time based on a result of comparison in said comparison process;
a limitation event generation process for generating a limitation event with respect to a production lot where said holding time violates said limitation time;
a production route determination process for determining a production procedure of a production lot in connection with said limitation event generated from irregular flow data having recorded a production procedure of a production lot violating the limitation time and said limitation time state data; and
a process for carrying out a production indication using a dispatching part immediately, in case a holding production lot violates the limitation time based on determination by said production route determination process.
According to this constitution of the method for forming a production plan, even in case the holding production lot violates the limitation time, a proper production indication can immediately be carried out.
In the above-mentioned constitution of the method for forming a production plan, it is desirable to further comprise:
an in-process work number calculation process for calculating out a production lot number being in process in said manufacturing processes from an in-process control data having recorded manufacturing processes where production in a particular production lot is stopped when a production lot number in manufacturing process in connection with a production order has reached a maximum production lot number that can be held in said manufacturing process, and in-process lot data showing positions of manufacturing processes where said production lots are in process in the production order;
an introduction lot control process for controlling an introduction to the manufacturing process relating to said production lot in accordance with said production lot number being in process and said in-process control data; and
a process for carrying out a production indication for maintaining the in-process lot number in the manufacturing process within a predetermined number using the dispatching part.
According to this constitution of the method for forming a production plan, in case the production lot number in process in the manufacturing process reaches the maximum number, by controlling the introduction of the production lot of the relating manufacturing process in the manufacturing processes, a production plan can be formed and a production indication can be carried out so that the lot number in process in the manufacturing processes can be maintained properly.
In the above-mentioned constitution of the method for forming a production plan, it is desirable to further comprise:
a grouping process for forming grouping data dynamically by being related to a production lot having completed production for each manufacturing apparatus based on a predetermined rule;
a representative lot judgment process for designating a production lot representing a group of the related production lots as a representative lot from said grouping data;
a representative lot control process for determining a particular production procedure for said representative lot;
a same group control process for carrying out an introduction control to a subsequent manufacturing process depending on state of the representative lot for a production lot of the same group other than said representative lot; and
a process for distinguishing a product procedure and for carrying out a production indication of the representative lot of production lots dynamically grouped using the dispatching part, and production lots of the same group, based on determination of said representative lot control process and said same group control process.
According to this constitution of the method for forming a production plan, a representative lot and other production lots are distinguished and a special production procedure is determined for the representative lot, and a production plan is formed and a production indication is carried out. By determining the subsequent process, and by carrying out the introduction control, based on production state of the representative lot with respect to the other lots than the representative lot, the representative lot of the production lots are actively grouped and other production lots are changed in the production procedure, and a production plan can be formed and a production indication can be carried out so that the introduction control can be carried out for the other production lots based on the representative lot state.
In the above-mentioned constitution of the method for forming a production plan, it is desirable to further determine an output of a production indication and for determining progress of a production lot, based on unit control data for controlling automation of a production indication for each manufacturing apparatus, process control data for controlling automation of a production indication for each production process in a production procedure, lot control data for controlling automation of lot progress for each production lot or product type, event control data for controlling automation of a production indication for each event forming a production plan, and event data from said event receiving process.
According to this constitution of the method for forming a production plan, the production plan can be formed and the production indication can be carried out based on the inputted control data, thereby it becomes possible for a manufacturing worker to give an indication for meticulous control.
A production plan forming apparatus according to the present invention comprises:
an input unit for inputting basic data necessary for forming a production procedure of production lots or a production plan having information on manufacturing apparatuses necessary for production, unit control data for controlling automation of a production indication for each manufacturing apparatus, process control data for controlling automation of a production indication for each production process in a production procedure, lot control data for controlling automation of lot progress for each production lot or product type, event control data for controlling automation of a production indication for each event forming a production plan;
a memory unit for storing each type of said data inputted from said input unit, state data changing with time indicating state of production lots and manufacturing apparatuses, event data relating to different events from a time production state changes, irregular flow data relating to a production procedure of production lots violating a limitation time, limitation time data relating to a holding time limitation of production lots in manufacturing process in connection with production orders, and production history data relating to production histories of production lots, limitation time state data relating to a limitation state by an entire lot holding time, in-process limitation data relating to a production lot number that can be in process in a manufacturing process and a manufacturing process an introduction control is carried out by that, in-process lot data relating to positions where production lots are in process, grouping data relating to production lot group related to a lot having completed in production for each manufacturing apparatus;
a central processing unit comprising; an event. receiving part for receiving an event of which production state changes, a pseudo event generation part for forming said event data and for generating a pseudo event, a holding time limitation observation part for changing a production procedure of production lots violating a holding limitation time in manufacturing process utilizing said irregular flow data, limitation time data, production history data, and limitation time state data, in-process number introduction control part for carrying out introduction limitation of production lots to said manufacturing apparatus to maintain an in-process lot number in a manufacturing process within a predetermined number utilizing said in-process control data and in-process lot data, dynamic lot group control part for distinguishing a representative lot of a production lot group grouped dynamically from a production procedure of other production lots utilizing said grouping data, an automatic planning control part for determining outputs of a production indication and for determining progress of production lots by receiving said unit control data, process control data, lot control data, event control data from the input unit, a dispatching part for carrying out a production indication by determining lots produced in said manufacturing apparatus among in-process lots; and
a display unit for displaying contents and forming state of the production plan.
According to the production plan forming apparatus of the present invention, basic data necessary for forming a production plan like the information on the manufacturing apparatus necessary for production procedure of the production lot or the production are inputted from the input unit and stored in the memory unit. The event receiving part receives the change of the production state as an event, the state date is stored in the memory unit, and the dispatching part forms the production plan of a certain manufacturing apparatus relating to the event and outputs the production instruction. At this time, in case the time when the event is received and the time when the production is indicated are different from each other, the event data is stored in the memory unit by means of the pseudo event production procedure, the event is generated at the time when the production indication is carried out and the production indication can be carried out by the dispatching part.
In case there are limitations in the holding time of the production lot, the limitation time data with respect to the holding time of the production lot in the manufacturing process in connection with the production order and irregular flow data with respect to the limitation procedure the production violated the limitation time have to pass through are inputted from the input unit and stored in the memory unit. Based on this limitation time data, irregular flow data and production history data relating to the production history of the production lots, an observance state of the limitation time is judged by the holding time limitation observation part, the limitation time state data are stored in the memory unit as well as the production procedure of the production lot having violated the limitation time is changed and the production indication can be carried out by the dispatching part.
In case the introduction control is carried out by the in-process lot number in the process, the production lot number which can be in process in a manufacturing process and in-process control data with respect to the manufacturing process carrying out the introduction control by that are inputted from the input unit and stored in the memory unit. Based on this in-process control data and in-process lot data with respect to the positions where the production lots are in-process, the in-process lot number between the manufacturing processes of the subsequent processes can be calculated out by the in-process number introduction control part, it can be determined whether the introduction to the manufacturing process with respect to the event is possible or not, the production indication can be carried out by the dispatching part.
In case the production lots are grouped to be controlled dynamically, the production lots having completed the production are related for each manufacturing apparatus by the dynamic lot group control part, grouping data can be stored in the memory unit, were representative lot of the group and other production lots are distinguished from this grouping data, and the production indication can be carried out by the dispatching part by determining each production procedure.
In case a manufacturing worker controls production indication, either one type of data in the following is inputted and stored in the memory unit: the unit control data for controlling automation of the production indication to each manufacturing apparatus from the input unit, the process control data for controlling automation of the production indication for each manufacturing process according to the production procedure, the lot control data for controlling automation of lot progress for each production lot or each product type, the event control data for controlling automation of the production indication for each event forming the production plan. By determining the lot progress for each production lot and existence of the output of the production indication by the automatic planning control procedure, the production indication can be carried out only when it is necessary by the dispatching part.
While the novel features of the invention are set forth particularly in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed description taken in conjunction with the drawings.